The present invention relates to a digital signal processing apparatus and, more particularly, to a digital signal processing apparatus having a memory for wave data consisting of a plurality of blocks wherein the blocks in the wave memory are automatically and incrementally addressed to sequentially receive waveform data of an input signal upon each measurement in a first mode, and in the second mode desired specific wave data is read out from a nonupdated block which has received the data in the first mode, thereby performing signal processing.
Conventional digital signal processing apparatuses are shown in FIGS. 1 and 2, respectively. According to these apparatuses, measurement of an analog signal wave is converted to a digital signal, and the digital signal is stored in a memory. The stored data is read out and processed for waveform analysis. The analyzed results are displayed on a display.
Referring to FIG. 1, a memory 12 for wave data comprises a plurality of blocks 12-1 to 12-N. Signal wave data digitized by an A/D converter 11 is stored in one of the blocks 12-1 to 12-N. Selection of the block in the memory 12 for storing the digital wave data is independently designated by an external block designating device 13. The wave data stored in the blocks 12-1 to 12-N of the memory 12 are selectively read out and fetched by a microprocessor 14. The readout data is processed as needed. Processed results are displayed on a display 15.
In another conventional digital signal processing apparatus shown in FIG. 2, a memory 12 for wave data comprises a signal block. N displaying screen memories 16 are arranged to display data processed by a microprocessor 14.
However, these conventional apparatuses have the following drawbacks. In the arrangement shown in FIG. 1, since the block in the memory 12 is independently designated, a single block may be repeatedly designated to update important signal wave data to new wave data, resulting in the undesirable loss of the prior data. In the arrangement of FIG. 2, since the memory 12 consists of a single block, once the stored data is updated with new input wave data, wave analysis and signal processing using the previous wave data cannot be performed.